Detection of myocardial dysfunction in the presence of normal ejection fraction

Experimental Research on the Evaluation of Left Ventricular Function by Layered Speckle Tracking in a Constrictive Pericarditis Rat Model

OBJECTIVES

In animal models with constrictive pericarditis (CP), detecting the function of cardiac systole by conventional noninvasive ultrasound is a challenge. We aimed to detect cardiac dysfunction in rat models with CP in the early stage by layered speckle tracking.

METHODS

We compared a rat CP model (n = 23, injected with a solution of 1-mg/mL lipopolysaccharides [0.5 mL] and a 10% talc suspension [0.5 mL]) with a control group (n = 20, no injection). After 8 weeks, conventional echocardiography and layered speckle tracking were used to assess the left ventricular structures and functions in the groups.

RESULTS

The global circumferential strain (CS) and longitudinal strain (LS) were decreased in the CP group (P < .05). The CS of the epicardial and middle layers in the CP group was decreased (P < .05), but the endocardial layer was not statistically different. The LS of the epicardial layer was decreased (P < .05), but the middle and endocardial layers were not statistically different. The global free-wall and septal-wall CS of the CP group was decreased (P < .05), mainly due to the decrease of CS of the epicardial and middle layers. The global free-wall LS of the CP group was decreased (P < .05), mainly due to the decrease of LS of the epicardial and middle layers. There were no significant differences between the groups in global LS of the septal wall.

CONCLUSIONS

In the early stage of CP, subepicardial myocardial damage precedes that of the subendocardial myocardium, and free-wall damage precedes that of the septal wall.

Reproducibility and Intervendor Agreement of Left Ventricular Global Systolic Strain in Children Using a Layer-Specific Analysis

BACKGROUND

Speckle-tracking strain analysis provides additive data to the assessment of pediatric and congenital heart disease; however, the variety of strain analysis software platforms by different vendors and the lack of data on intervendor strain agreement in children have limited its utility. The purpose of this study is to evaluate the intervendor agreement of strain on two commonly used analysis platforms in pediatrics by layer of myocardium and data compression.

METHODS

This prospective study analyzed two-dimensional speckle-tracking strain on two software platforms in 53 children with normal cardiac segmental anatomy and varying function. Three standard apical views and one parasternal short-axis view were exported at their acquired frame rates to workstations with GE EchoPAC and TomTec software and then also to TomTec at compressed frame rates. Both software platforms had been updated with European Association of Cardiovascular Imaging/American Society of Echocardiography Task Force recommendations for left ventricular (LV) global strain. Intravendor and intervendor agreement between layer-specific comparisons were assessed using Bland-Altman analysis (limits of agreement and bias) and intraclass correlation coefficients.

RESULTS

This study included subjects with normal LV function (n = 38) and cardiomyopathy (n = 15) with an age range of 1 month to 18 years. Intertechnique agreement by default vendor myocardial layer (GE mid-TomTec endocardial layer) was robust for both global longitudinal (GLS) and circumferential strain (GCS; higher for GLS than GCS). Intravendor (inter- and interreader) agreement was slightly higher than intervendor. Only small differences in intraclass correlation coefficients were present between various myocardial layers and acquired versus compressed TomTec data with narrow limits of agreement and small bias except in certain subgroup comparisons.

CONCLUSIONS

Comparison of LV GLS and GCS between two commonly used software platforms after European Association of Cardiovascular Imaging/American Society of Echocardiography Industry Task Force recommendations demonstrated good to excellent agreement in pediatrics, regardless of the layer of analysis or the image format, although some degree of variability remains between vendor platforms. Overall, GLS agreement was more robust than GCS, and this difference is exaggerated in specific subanalyses. These data suggest that comparisons of strain values obtained on these two vendors will be reasonable, but caution should be used when the indication is the detection of small differences between serial echocardiograms.

Myocardial function in patients with anomalous left coronary artery from the pulmonary artery syndrome: A long-term speckle tracking echocardiographic study

Background

Anomalous origin of the left coronary artery (LCA) from the pulmonary artery (ALCAPA) is a rare congenital heart disease. Retrograde flow from the right coronary artery (RCA) through natural collaterals to the low-pressure main pulmonary artery causes extensive ischemia. Limited data concerning the extent of permanent myocardial damage and functional recovery after surgical repair in the long-term follow-up is available.

Aim

Determination of the incidence of incipient myocardial dysfunction in ALCAPA patients in the long-term observation using tissue Doppler and speckle tracking echocardiography.

Methods and results

Eighteen ALCAPA patients after surgical repair (at median age of 7 months, range 3–167) underwent echocardiographic examination after (median) 17 years. All but 4 patients in NYHA class II presented well at follow-up. No narrowing in proximal LCA was detected in color Doppler. The initial (pre-surgical) left ventricular (LV) ejection fraction of 33±17% almost normalized to 55±6%, but was lower than in the age, sex and body surface area matched control group: 62±5% (p<0.001). At follow-up, LV global longitudinal strain (LS): -15.8±3.3% vs -21.9±1.7%; right ventricular LS: -20.6±3.9% vs -24.9±4.6%; left atrial LS: 27.7±4.3% vs 41.0±11.5%; right atrial LS: 26.8±7.4% vs 44.0±7.9% and early pulsed wave to tissue Doppler mitral filling ratio (E/E’): 8.1±2.6 vs 5.8±1.3 were impaired in the ALCAPA population in comparison to the control group (p<0.01 for all comparisons). LV radial and circumferential strain did not differ between groups. Mean LS in the ALCAPA patients in the RCA region was -19.0±4.4%, while in the LCA region -13.8±7.3% (p<0.00001).

Conclusions

Despite good clinical condition and normalized LV ejection fraction in ALCAPA patients after surgical repair in the long-term follow-up, the diastolic and longitudinal systolic function of all cardiac chambers remained impaired, especially in the LCA region. Lifelong surveillance of repaired ALCAPA patients is needed.

Left ventricular strain is associated with acute postoperative refractory hypotension in patients with constrictive pericarditis and preserved ejection fraction

Background

Pericardiectomy is an effective treatment for constrictive pericarditis (CP). Early postoperative complications such as refractory hypotension and congestive heart failure occur in these patients and are associated with increased morbidity and mortality. We hypothesized that left ventricular (LV) myocardial strain measured by two-dimensional speckle tracking echocardiography (2DSTE) could identify early cardiac dysfunction and relate to acute postoperative adverse events in CP patients.

Methods

Forty-four CP patients with preserved left ventricular ejection fraction (LVpEF, 64%±8%) and 44 age- and sex-matched controls were enrolled. Conventional 2DSTE was performed before pericardiectomy. Global and segmental peak systolic strain values were measured. The primary endpoint was a composite of postoperative refractory hypotension, congestive heart failure and cardiogenic death. Refractory hypotension was defined as hypotension requiring prolonged usage of intravenous inotropic medication (IVIM) (≥2 days).

Results

Postoperative refractory hypotension occurred in 26 cases, and no patients experienced congestive heart failure or cardiogenic death. Compared to controls, CP patients had decreased absolute global and segmental circumferential strain (CS), radial strain (RS), and longitudinal strain (LS) except septal LS. Patients with refractory hypotension exhibited lower epicardial CS (P=0.04). Epicardial CS was an independent risk factor correlated with postoperative adverse outcome [P=0.014, OR =1.236 (1.044-1.464)] while LVEF was not. Lower absolute value of epicardial CS was related to higher (P=0.02) and longer usage of intravenous furosemide (P=0.04) to keep negative fluid balance perioperatively.

Conclusions

LV strain value is markedly reduced in patients with CP and LVpEF. Lower preoperative epicardial CS value is associated with greater risk of early refractory hypotension and more aggressive fluid management.

Global longitudinal strain as a potential prognostic marker in patients with chronic heart failure and systolic dysfunction

INTRODUCTION AND OBJECTIVE

The prognostic value of myocardium deformation measurements in chronic heart failure (CHF) is still poorly addressed. The purpose of this study was to evaluate the correlation of left ventricular (LV) global longitudinal strain (GLS) with clinical and prognostic indicators in patients with CHF and systolic dysfunction.

METHODS

Ambulatory patients with CHF and LV ejection fraction (LVEF) <45% were studied by two-dimensional and Doppler transthoracic echocardiogram with assessment of GLS. An indication of prognostic status was obtained by the Seattle Heart Failure Model (SHFM) prognostic estimates for life expectancy.

RESULTS

We included 54 CHF patients (mean age 55±12 years; 80% male). GLS was significantly correlated with NYHA functional class (r=0.41, p=0.002), BNP levels (r=0.47, p=0.001), LVEF (r=-0.69, p<0.001) and LV end-diastolic pressure, assessed by E/e' ratio (r=0.35, p<0.014) and left atrial maximal volume index (r=0.57, p<0.001). A significant correlation was found between GLS and SHFM prognostic estimates for life expectancy (r=-0.41, p=0.002). The multivariate logistic regression analysis showed that GLS independently predicted an estimated life expectancy <10 years (OR 2.614 [95% CI 1.010-6.763]). The corresponding area under the ROC curve was 0.802 (0.653-0.951) and the best obtained threshold was -9.5 (80% sensitivity, 65% specificity, p=0.003).

CONCLUSIONS

GLS was strongly associated with a higher disease severity status and predicted a lower prognostic estimate for life expectancy.

Diastolic dysfunction in women with signs and symptoms of ischemia in the absence of obstructive coronary artery disease: a hypothesis-generating study

BACKGROUND

Angina, in the absence of obstructive coronary artery disease, is more common in women, is associated with adverse cardiovascular morbidity and mortality, and is a major burden to the healthcare system. Although advancements have been made to understand the mechanistic underpinning of this disease, the functional consequence remains unclear.

METHODS AND RESULTS

Cardiac magnetic resonance imaging was performed to assess left ventricular function in 20 women with signs and symptoms of ischemia, but no obstructive coronary artery disease (cases), and 15 age- and body mass index-matched reference controls. Functional imaging included standard cinematic imaging to assess left ventricular morphology and global function, along with tissue tagging to assess left ventricular tissue deformation. Systolic function was preserved in both cases and controls, with no differences in ejection fraction (mean±SE: 63.1±8% versus 65±2%), circumferential strain (-20.7±0.6% versus -21.9±0.5%), or systolic circumferential strain rate (-105.9±6.1% versus -109.0±3.8% per second). In contrast, we observed significant differences between cases and controls in diastolic function, as demonstrated by reductions in both diastolic circumferential strain rate (153.8±8.9% versus 191.4±8.9% per second; P<0.05) and peak rate of left ventricular untwisting (-99.4±8.0° versus -129.4±12.8° per second; P<0.05).

CONCLUSIONS

Diastolic function is impaired in women with signs and symptoms of ischemia in the absence of coronary artery disease, as assessed by cardiac magnetic resonance tissue tagging. These results are hypothesis-generating. Larger studies are needed to define the exact mechanism(s) responsible and to establish viable treatment strategies.

Abnormal cardiac strain in children and young adults with HIV acquired in early life

BACKGROUND

Traditional measures of cardiac function are now often normal in adolescents and young adults treated with antiretroviral therapy for human immunodeficiency virus (HIV) infection. There is, however, evidence of myocardial abnormalities in adults with HIV. Cardiac strain analysis may detect impairment in cardiac function that may be missed by conventional measurements in this population.

METHODS

This was a retrospective study in which echocardiograms of HIV-infected subjects (n = 28) aged 7 to 29 years who participate in a natural history study of HIV acquired early in life were analyzed and compared with matched controls. Standard echocardiographic measures, along with speckle tracking-derived strain and strain rate, were assessed.

RESULTS

Among the HIV-infected subjects, the median CD4 count was 667 cells/mm(3), and the mean duration of antiretroviral therapy was 14.6 years. Ejection fractions and fractional shortening were normal. There were no significant differences in measures of systolic or diastolic function between the groups. The HIV-infected group had borderline increased left ventricular mass indices. Global longitudinal and circumferential strain and strain rate, as well as global radial strain rate, were significantly impaired in the HIV-infected group compared with controls. There were no associations identified between left ventricular mass index or strain indices and current CD4 count, CD4 nadir, HIV viral load, or duration of antiretroviral therapy.

CONCLUSIONS

HIV-infected participants demonstrated impaired strain and strain rate despite having normal systolic function and ejection fractions. Strain and strain rate may prove to be prognostic factors for long-term myocardial dysfunction. Therefore, asymptomatic children and young adults with long-standing HIV infection may benefit from these more sensitive measures.

Multimodality Imaging in Congenital Heart Disease: an Update

The increasing number of survivors of congenital heart disease (CHD) has been paralleled by advancement of imaging modalities used for the ongoing assessment of these patients. There has been a large body of literature describing new approaches to non-invasive assessment of CHD. We will review new applications of well established as well as novel techniques for the management and understanding of CHD.

Heart failure in 2010

The Heart Failure Congress 2010 in Berlin presented the latest trials and trends in the medical and mechanical therapy of heart failure in the presence of impaired or preserved left ventricular ejection fraction. It covered all aspects of heart failure from epidemiology through basic and translational science to prevention. The congress highlighted new drugs, novel biomarkers, updated trials, the role of imaging in risk stratification and the importance of telecare in the reduction of heart failure readmission.